In response to PA-12-127, seeking research addressing utilization, effectiveness, appropriateness, and/or costs of treatment and prevention services, this application proposes an open-label, randomized trial of two depot pharmacotherapies compared to each other and to psychosocial treatment as usual. This study will examine the feasibility and utility of depot formulations of a partial opioid agonist (buprenorphine, as Probuphine) and an opioid antagonist (naltrexone, as Vivitrol) for preventing relapse to opioid addiction and associated criminal activity among opioid-dependent individuals in jail. Pharmacotherapy with methadone, buprenorphine, or naltrexone has been proven to be efficacious in managing opioid addiction. However, methadone is burdened with regulatory constraints, oral naltrexone has poor patient acceptance, and oral buprenorphine suffers from non-adherence, misuse, and diversion. The majority of opioid addicts released from incarceration do not follow through on referrals to treatment in the community, and relapse to opioid use occurs in the majority of prisoners within one month after release. By overcoming the problem of poor adherence to medication, depot pharmacotherapies offer means to effectively prevent relapse and associated costs, such as emergency room visits, lost wages, and criminal activity and re-incarceration. However, depot medications are expensive-exceeding $500 a month-and the return on this investment with drug-involved offenders has yet to be determined. The study design includes a 4-year plan to investigate the two depot medications in samples of detoxified opioid addicts in Ventura County Jail. Participants (N=150) will be randomly assigned to a 6-month intervention condition of Vivitrol (n=50), Probuphine (n=50), or no medication (n=50); all participants are referred to manual-guided psychosocial treatment in the community. As recommended by reviewers of the original application, the no-medication group serves as a control condition and thus is provided psychosocial treatment only. In addition to bi-weekly urine tests and medical management (plus supplemental monitoring via weekly telephone contact) during the 6-month intervention- phase of the trial, participants will participate in extensive assessments at 1, 6, and 12 months post- randomization. Outcomes include opioid use (and use of other substances), criminal activity, and economic benefits associated with the three conditions. The cost analysis will measure and value resources associated with the Probuphine and Vivitrol pharmacotherapies, including medical personnel (physician/nurses), labs, and medications. Other costs, such as those related to pre-release detoxification and to post-release check-ups, are common across the three study conditions. To ascertain cost-effectiveness ratios of Probuphine and Vivitrol, cost data will be compared to changes in key clinical measures of effectiveness (e.g., time to relapse, days of abstinence, re-arrest).